According to Peter Kafka at All Thing D, Twitter is considering another revenue-generating initiative besides its already announced in-stream advertising.

The idea, Kafka says, is to offer “promoted trends” to advertisers. The way it would likely work is that an advertiser could choose a term that would appear on twitter’s homepage in the “trending topics” area.

Clicking on that term would call up a Twitter search results page, which would feature that advertisers’ “Promoted Tweet” at the top of the results.

Advertisers who have heard Twitter talk about the product say the service imagines charging “tens of thousands of dollars” a day for exclusive placement rights.

Of course, Twitter already has a problem with Spam, and there is always the potential for shenanigans, as was the case when Skittles launched an unusual marketing campaign with Twitter last year.